net/mlx4_en: Fix mixed PFC and Global pause user control requests
[pandora-kernel.git] / net / sunrpc / auth.c
1 /*
2  * linux/net/sunrpc/auth.c
3  *
4  * Generic RPC client authentication API.
5  *
6  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7  */
8
9 #include <linux/types.h>
10 #include <linux/sched.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/errno.h>
14 #include <linux/hash.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/spinlock.h>
17
18 #ifdef RPC_DEBUG
19 # define RPCDBG_FACILITY        RPCDBG_AUTH
20 #endif
21
22 #define RPC_CREDCACHE_DEFAULT_HASHBITS  (4)
23 struct rpc_cred_cache {
24         struct hlist_head       *hashtable;
25         unsigned int            hashbits;
26         spinlock_t              lock;
27 };
28
29 static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
30
31 static DEFINE_SPINLOCK(rpc_authflavor_lock);
32 static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
33         &authnull_ops,          /* AUTH_NULL */
34         &authunix_ops,          /* AUTH_UNIX */
35         NULL,                   /* others can be loadable modules */
36 };
37
38 static LIST_HEAD(cred_unused);
39 static unsigned long number_cred_unused;
40
41 #define MAX_HASHTABLE_BITS (14)
42 static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
43 {
44         unsigned long num;
45         unsigned int nbits;
46         int ret;
47
48         if (!val)
49                 goto out_inval;
50         ret = strict_strtoul(val, 0, &num);
51         if (ret == -EINVAL)
52                 goto out_inval;
53         nbits = fls(num);
54         if (num > (1U << nbits))
55                 nbits++;
56         if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
57                 goto out_inval;
58         *(unsigned int *)kp->arg = nbits;
59         return 0;
60 out_inval:
61         return -EINVAL;
62 }
63
64 static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
65 {
66         unsigned int nbits;
67
68         nbits = *(unsigned int *)kp->arg;
69         return sprintf(buffer, "%u", 1U << nbits);
70 }
71
72 #define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
73
74 static struct kernel_param_ops param_ops_hashtbl_sz = {
75         .set = param_set_hashtbl_sz,
76         .get = param_get_hashtbl_sz,
77 };
78
79 module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
80 MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
81
82 static u32
83 pseudoflavor_to_flavor(u32 flavor) {
84         if (flavor >= RPC_AUTH_MAXFLAVOR)
85                 return RPC_AUTH_GSS;
86         return flavor;
87 }
88
89 int
90 rpcauth_register(const struct rpc_authops *ops)
91 {
92         rpc_authflavor_t flavor;
93         int ret = -EPERM;
94
95         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
96                 return -EINVAL;
97         spin_lock(&rpc_authflavor_lock);
98         if (auth_flavors[flavor] == NULL) {
99                 auth_flavors[flavor] = ops;
100                 ret = 0;
101         }
102         spin_unlock(&rpc_authflavor_lock);
103         return ret;
104 }
105 EXPORT_SYMBOL_GPL(rpcauth_register);
106
107 int
108 rpcauth_unregister(const struct rpc_authops *ops)
109 {
110         rpc_authflavor_t flavor;
111         int ret = -EPERM;
112
113         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
114                 return -EINVAL;
115         spin_lock(&rpc_authflavor_lock);
116         if (auth_flavors[flavor] == ops) {
117                 auth_flavors[flavor] = NULL;
118                 ret = 0;
119         }
120         spin_unlock(&rpc_authflavor_lock);
121         return ret;
122 }
123 EXPORT_SYMBOL_GPL(rpcauth_unregister);
124
125 struct rpc_auth *
126 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
127 {
128         struct rpc_auth         *auth;
129         const struct rpc_authops *ops;
130         u32                     flavor = pseudoflavor_to_flavor(pseudoflavor);
131
132         auth = ERR_PTR(-EINVAL);
133         if (flavor >= RPC_AUTH_MAXFLAVOR)
134                 goto out;
135
136         if ((ops = auth_flavors[flavor]) == NULL)
137                 request_module("rpc-auth-%u", flavor);
138         spin_lock(&rpc_authflavor_lock);
139         ops = auth_flavors[flavor];
140         if (ops == NULL || !try_module_get(ops->owner)) {
141                 spin_unlock(&rpc_authflavor_lock);
142                 goto out;
143         }
144         spin_unlock(&rpc_authflavor_lock);
145         auth = ops->create(clnt, pseudoflavor);
146         module_put(ops->owner);
147         if (IS_ERR(auth))
148                 return auth;
149         if (clnt->cl_auth)
150                 rpcauth_release(clnt->cl_auth);
151         clnt->cl_auth = auth;
152
153 out:
154         return auth;
155 }
156 EXPORT_SYMBOL_GPL(rpcauth_create);
157
158 void
159 rpcauth_release(struct rpc_auth *auth)
160 {
161         if (!atomic_dec_and_test(&auth->au_count))
162                 return;
163         auth->au_ops->destroy(auth);
164 }
165
166 static DEFINE_SPINLOCK(rpc_credcache_lock);
167
168 static void
169 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
170 {
171         hlist_del_rcu(&cred->cr_hash);
172         smp_mb__before_clear_bit();
173         clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
174 }
175
176 static int
177 rpcauth_unhash_cred(struct rpc_cred *cred)
178 {
179         spinlock_t *cache_lock;
180         int ret;
181
182         cache_lock = &cred->cr_auth->au_credcache->lock;
183         spin_lock(cache_lock);
184         ret = atomic_read(&cred->cr_count) == 0;
185         if (ret)
186                 rpcauth_unhash_cred_locked(cred);
187         spin_unlock(cache_lock);
188         return ret;
189 }
190
191 /*
192  * Initialize RPC credential cache
193  */
194 int
195 rpcauth_init_credcache(struct rpc_auth *auth)
196 {
197         struct rpc_cred_cache *new;
198         unsigned int hashsize;
199
200         new = kmalloc(sizeof(*new), GFP_KERNEL);
201         if (!new)
202                 goto out_nocache;
203         new->hashbits = auth_hashbits;
204         hashsize = 1U << new->hashbits;
205         new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
206         if (!new->hashtable)
207                 goto out_nohashtbl;
208         spin_lock_init(&new->lock);
209         auth->au_credcache = new;
210         return 0;
211 out_nohashtbl:
212         kfree(new);
213 out_nocache:
214         return -ENOMEM;
215 }
216 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
217
218 /*
219  * Destroy a list of credentials
220  */
221 static inline
222 void rpcauth_destroy_credlist(struct list_head *head)
223 {
224         struct rpc_cred *cred;
225
226         while (!list_empty(head)) {
227                 cred = list_entry(head->next, struct rpc_cred, cr_lru);
228                 list_del_init(&cred->cr_lru);
229                 put_rpccred(cred);
230         }
231 }
232
233 /*
234  * Clear the RPC credential cache, and delete those credentials
235  * that are not referenced.
236  */
237 void
238 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
239 {
240         LIST_HEAD(free);
241         struct hlist_head *head;
242         struct rpc_cred *cred;
243         unsigned int hashsize = 1U << cache->hashbits;
244         int             i;
245
246         spin_lock(&rpc_credcache_lock);
247         spin_lock(&cache->lock);
248         for (i = 0; i < hashsize; i++) {
249                 head = &cache->hashtable[i];
250                 while (!hlist_empty(head)) {
251                         cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
252                         get_rpccred(cred);
253                         if (!list_empty(&cred->cr_lru)) {
254                                 list_del(&cred->cr_lru);
255                                 number_cred_unused--;
256                         }
257                         list_add_tail(&cred->cr_lru, &free);
258                         rpcauth_unhash_cred_locked(cred);
259                 }
260         }
261         spin_unlock(&cache->lock);
262         spin_unlock(&rpc_credcache_lock);
263         rpcauth_destroy_credlist(&free);
264 }
265
266 /*
267  * Destroy the RPC credential cache
268  */
269 void
270 rpcauth_destroy_credcache(struct rpc_auth *auth)
271 {
272         struct rpc_cred_cache *cache = auth->au_credcache;
273
274         if (cache) {
275                 auth->au_credcache = NULL;
276                 rpcauth_clear_credcache(cache);
277                 kfree(cache->hashtable);
278                 kfree(cache);
279         }
280 }
281 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
282
283
284 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
285
286 /*
287  * Remove stale credentials. Avoid sleeping inside the loop.
288  */
289 static int
290 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
291 {
292         spinlock_t *cache_lock;
293         struct rpc_cred *cred, *next;
294         unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
295
296         list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
297
298                 if (nr_to_scan-- == 0)
299                         break;
300                 /*
301                  * Enforce a 60 second garbage collection moratorium
302                  * Note that the cred_unused list must be time-ordered.
303                  */
304                 if (time_in_range(cred->cr_expire, expired, jiffies) &&
305                     test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
306                         return 0;
307
308                 list_del_init(&cred->cr_lru);
309                 number_cred_unused--;
310                 if (atomic_read(&cred->cr_count) != 0)
311                         continue;
312
313                 cache_lock = &cred->cr_auth->au_credcache->lock;
314                 spin_lock(cache_lock);
315                 if (atomic_read(&cred->cr_count) == 0) {
316                         get_rpccred(cred);
317                         list_add_tail(&cred->cr_lru, free);
318                         rpcauth_unhash_cred_locked(cred);
319                 }
320                 spin_unlock(cache_lock);
321         }
322         return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
323 }
324
325 /*
326  * Run memory cache shrinker.
327  */
328 static int
329 rpcauth_cache_shrinker(struct shrinker *shrink, struct shrink_control *sc)
330 {
331         LIST_HEAD(free);
332         int res;
333         int nr_to_scan = sc->nr_to_scan;
334         gfp_t gfp_mask = sc->gfp_mask;
335
336         if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
337                 return (nr_to_scan == 0) ? 0 : -1;
338         if (list_empty(&cred_unused))
339                 return 0;
340         spin_lock(&rpc_credcache_lock);
341         res = rpcauth_prune_expired(&free, nr_to_scan);
342         spin_unlock(&rpc_credcache_lock);
343         rpcauth_destroy_credlist(&free);
344         return res;
345 }
346
347 /*
348  * Look up a process' credentials in the authentication cache
349  */
350 struct rpc_cred *
351 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
352                 int flags)
353 {
354         LIST_HEAD(free);
355         struct rpc_cred_cache *cache = auth->au_credcache;
356         struct hlist_node *pos;
357         struct rpc_cred *cred = NULL,
358                         *entry, *new;
359         unsigned int nr;
360
361         nr = hash_long(acred->uid, cache->hashbits);
362
363         rcu_read_lock();
364         hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
365                 if (!entry->cr_ops->crmatch(acred, entry, flags))
366                         continue;
367                 spin_lock(&cache->lock);
368                 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
369                         spin_unlock(&cache->lock);
370                         continue;
371                 }
372                 cred = get_rpccred(entry);
373                 spin_unlock(&cache->lock);
374                 break;
375         }
376         rcu_read_unlock();
377
378         if (cred != NULL)
379                 goto found;
380
381         new = auth->au_ops->crcreate(auth, acred, flags);
382         if (IS_ERR(new)) {
383                 cred = new;
384                 goto out;
385         }
386
387         spin_lock(&cache->lock);
388         hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
389                 if (!entry->cr_ops->crmatch(acred, entry, flags))
390                         continue;
391                 cred = get_rpccred(entry);
392                 break;
393         }
394         if (cred == NULL) {
395                 cred = new;
396                 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
397                 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
398         } else
399                 list_add_tail(&new->cr_lru, &free);
400         spin_unlock(&cache->lock);
401 found:
402         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
403             cred->cr_ops->cr_init != NULL &&
404             !(flags & RPCAUTH_LOOKUP_NEW)) {
405                 int res = cred->cr_ops->cr_init(auth, cred);
406                 if (res < 0) {
407                         put_rpccred(cred);
408                         cred = ERR_PTR(res);
409                 }
410         }
411         rpcauth_destroy_credlist(&free);
412 out:
413         return cred;
414 }
415 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
416
417 struct rpc_cred *
418 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
419 {
420         struct auth_cred acred;
421         struct rpc_cred *ret;
422         const struct cred *cred = current_cred();
423
424         dprintk("RPC:       looking up %s cred\n",
425                 auth->au_ops->au_name);
426
427         memset(&acred, 0, sizeof(acred));
428         acred.uid = cred->fsuid;
429         acred.gid = cred->fsgid;
430         acred.group_info = get_group_info(((struct cred *)cred)->group_info);
431
432         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
433         put_group_info(acred.group_info);
434         return ret;
435 }
436
437 void
438 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
439                   struct rpc_auth *auth, const struct rpc_credops *ops)
440 {
441         INIT_HLIST_NODE(&cred->cr_hash);
442         INIT_LIST_HEAD(&cred->cr_lru);
443         atomic_set(&cred->cr_count, 1);
444         cred->cr_auth = auth;
445         cred->cr_ops = ops;
446         cred->cr_expire = jiffies;
447 #ifdef RPC_DEBUG
448         cred->cr_magic = RPCAUTH_CRED_MAGIC;
449 #endif
450         cred->cr_uid = acred->uid;
451 }
452 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
453
454 struct rpc_cred *
455 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
456 {
457         dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
458                         cred->cr_auth->au_ops->au_name, cred);
459         return get_rpccred(cred);
460 }
461 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
462
463 static struct rpc_cred *
464 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
465 {
466         struct rpc_auth *auth = task->tk_client->cl_auth;
467         struct auth_cred acred = {
468                 .uid = 0,
469                 .gid = 0,
470         };
471
472         dprintk("RPC: %5u looking up %s cred\n",
473                 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
474         return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
475 }
476
477 static struct rpc_cred *
478 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
479 {
480         struct rpc_auth *auth = task->tk_client->cl_auth;
481
482         dprintk("RPC: %5u looking up %s cred\n",
483                 task->tk_pid, auth->au_ops->au_name);
484         return rpcauth_lookupcred(auth, lookupflags);
485 }
486
487 static int
488 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
489 {
490         struct rpc_rqst *req = task->tk_rqstp;
491         struct rpc_cred *new;
492         int lookupflags = 0;
493
494         if (flags & RPC_TASK_ASYNC)
495                 lookupflags |= RPCAUTH_LOOKUP_NEW;
496         if (cred != NULL)
497                 new = cred->cr_ops->crbind(task, cred, lookupflags);
498         else if (flags & RPC_TASK_ROOTCREDS)
499                 new = rpcauth_bind_root_cred(task, lookupflags);
500         else
501                 new = rpcauth_bind_new_cred(task, lookupflags);
502         if (IS_ERR(new))
503                 return PTR_ERR(new);
504         if (req->rq_cred != NULL)
505                 put_rpccred(req->rq_cred);
506         req->rq_cred = new;
507         return 0;
508 }
509
510 void
511 put_rpccred(struct rpc_cred *cred)
512 {
513         /* Fast path for unhashed credentials */
514         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
515                 if (atomic_dec_and_test(&cred->cr_count))
516                         cred->cr_ops->crdestroy(cred);
517                 return;
518         }
519
520         if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
521                 return;
522         if (!list_empty(&cred->cr_lru)) {
523                 number_cred_unused--;
524                 list_del_init(&cred->cr_lru);
525         }
526         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
527                 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
528                         cred->cr_expire = jiffies;
529                         list_add_tail(&cred->cr_lru, &cred_unused);
530                         number_cred_unused++;
531                         goto out_nodestroy;
532                 }
533                 if (!rpcauth_unhash_cred(cred)) {
534                         /* We were hashed and someone looked us up... */
535                         goto out_nodestroy;
536                 }
537         }
538         spin_unlock(&rpc_credcache_lock);
539         cred->cr_ops->crdestroy(cred);
540         return;
541 out_nodestroy:
542         spin_unlock(&rpc_credcache_lock);
543 }
544 EXPORT_SYMBOL_GPL(put_rpccred);
545
546 __be32 *
547 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
548 {
549         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
550
551         dprintk("RPC: %5u marshaling %s cred %p\n",
552                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
553
554         return cred->cr_ops->crmarshal(task, p);
555 }
556
557 __be32 *
558 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
559 {
560         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
561
562         dprintk("RPC: %5u validating %s cred %p\n",
563                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
564
565         return cred->cr_ops->crvalidate(task, p);
566 }
567
568 static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
569                                    __be32 *data, void *obj)
570 {
571         struct xdr_stream xdr;
572
573         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
574         encode(rqstp, &xdr, obj);
575 }
576
577 int
578 rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
579                 __be32 *data, void *obj)
580 {
581         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
582
583         dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
584                         task->tk_pid, cred->cr_ops->cr_name, cred);
585         if (cred->cr_ops->crwrap_req)
586                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
587         /* By default, we encode the arguments normally. */
588         rpcauth_wrap_req_encode(encode, rqstp, data, obj);
589         return 0;
590 }
591
592 static int
593 rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
594                           __be32 *data, void *obj)
595 {
596         struct xdr_stream xdr;
597
598         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
599         return decode(rqstp, &xdr, obj);
600 }
601
602 int
603 rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
604                 __be32 *data, void *obj)
605 {
606         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
607
608         dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
609                         task->tk_pid, cred->cr_ops->cr_name, cred);
610         if (cred->cr_ops->crunwrap_resp)
611                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
612                                                    data, obj);
613         /* By default, we decode the arguments normally. */
614         return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
615 }
616
617 int
618 rpcauth_refreshcred(struct rpc_task *task)
619 {
620         struct rpc_cred *cred;
621         int err;
622
623         cred = task->tk_rqstp->rq_cred;
624         if (cred == NULL) {
625                 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
626                 if (err < 0)
627                         goto out;
628                 cred = task->tk_rqstp->rq_cred;
629         }
630         dprintk("RPC: %5u refreshing %s cred %p\n",
631                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
632
633         err = cred->cr_ops->crrefresh(task);
634 out:
635         if (err < 0)
636                 task->tk_status = err;
637         return err;
638 }
639
640 void
641 rpcauth_invalcred(struct rpc_task *task)
642 {
643         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
644
645         dprintk("RPC: %5u invalidating %s cred %p\n",
646                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
647         if (cred)
648                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
649 }
650
651 int
652 rpcauth_uptodatecred(struct rpc_task *task)
653 {
654         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
655
656         return cred == NULL ||
657                 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
658 }
659
660 static struct shrinker rpc_cred_shrinker = {
661         .shrink = rpcauth_cache_shrinker,
662         .seeks = DEFAULT_SEEKS,
663 };
664
665 int __init rpcauth_init_module(void)
666 {
667         int err;
668
669         err = rpc_init_authunix();
670         if (err < 0)
671                 goto out1;
672         err = rpc_init_generic_auth();
673         if (err < 0)
674                 goto out2;
675         register_shrinker(&rpc_cred_shrinker);
676         return 0;
677 out2:
678         rpc_destroy_authunix();
679 out1:
680         return err;
681 }
682
683 void rpcauth_remove_module(void)
684 {
685         rpc_destroy_authunix();
686         rpc_destroy_generic_auth();
687         unregister_shrinker(&rpc_cred_shrinker);
688 }